This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The goal of this project is to define the effects of different structural forms of the aggregated protein A[unreadable] on the brain. In Alzheimer's disease, A[unreadable] (a protein normally generated by brain cells) becomes misfolded and binds to other A[unreadable] molecules, forming senile plaques and cerebral amyloid angiopathy. Our lab has shown that the aggregation of A[unreadable] can be stimulated by exposure to brain extracts from patients with Alzheimer's disease. This past year we have begun studies to isolate the seed itself, to assess its ability to induce aggregation, and to determine whether there are different structural/functional subtypes of A[unreadable].